Summary: S1Supplemental Data
Audiovisual Integration of Speech
Falters under High Attention Demands
Agne` s Alsius, Jordi Navarra, Ruth Campbell,
and Salvador Soto-Faraco
Supplemental Results ments 1 and 2 in terms of hits or false alarms, indicating that second-
ary tasks of both experiments were well matched for difficulty.
Recall of Filler Words
The recall accuracy for the filler words (audiovisually congruent, yet Supplemental Experimental Procedures
submitted to the same dubbing procedures as the main materials)
in Experiment 1 was audiovisual .99, auditory alone .93, and Participants
visual alone .06 for the dual task and .96, .93, and .06, respectively, Thirty-six undergraduate students (18 in each experiment) from the
for the single task. In Experiment 2, the corresponding proportions University of Barcelona participated in the study in exchange for
were, respectively, .96, .88, and .05 for the dual task and .93, .87, course credit. None of them had a reported history of hearing disor-
and .14 for the single task. ders, and all had normal or corrected-to-normal vision.
StimuliTarget Detection in the Concurrent Task
Both hits and false-alarm (fa) rates in the concurrent repetition task Pairs of meaningful Spanish words were selected according to the
phonetic properties previously shown to give rise to the McGurkwere analyzed for participants serving in the dual-task condition of
both experiments. In Experiment 1, the overall hit rate was 0.42, effect when artificially dubbed. In particular, the visual and auditory
words were phonetically identical except for one phoneme; thisand the false-alarm rate (responding outside a 1 s window from a